The objective of this paper is to determine the plastic limit moment for cylindrical vessels with a nozzle under in-plane moment loading. Three full scale test models with different d/D ratios were fabricated for the experiment. A three-dimensional nonlinear finite element analysis was also performed. The plastic limit moment of the cylindrical vessel-nozzle connections was determined approximately by the twice-elastic-slope criterion. The results indicate that the plastic limit moments obtained by the experiment and finite element analysis are in good agreement. On the basis of the above results, a parametric analysis of the plastic limit moment for cylindrical vessels under in-plane moment on the nozzle was carried out, and an empirical formula is proposed. The results can serve as a supplement to the available data of plastic limit load for cylindrical vessel-nozzle connection structures under external load.

Issue Section:
Design and Analysis
Keywords:
vessel-nozzle connection, in-plane moment, plastic limit load, experimental study, finite element analysis, elastic limit, finite element analysis, nozzles, plasticity, pressure vessels, shapes (structures)
Topics:
Finite element analysis, Nozzles, Stress, Vessels, Deformation
1.
2004,
ASME Boiler and Pressure Vessel Code, Sec. VIII, Division 2
, 2004 ed.,
American Society of Mechanical Engineering
,
New York
.
2.
Ellyin
,
F.
, 1976, “
Experimental Investigation of Limit Loads of Nozzles in Cylindrical Vessels
,” Welding Research Council Bulletin, Paper No. 219.
3.
Ellyin
,
F.
, 1977, “
An Experimental Study of Elastic-Plastic Response of Branch Pipe Tee Connection Subjected to Internal Pressure, External Couples and Combined Loadings
,” Welding Research Council Bulletin, Paper No. 230.
4.
Schroeder
,
J.
, 1985, “
Experimental Limit Couples for Branch Moment Loads on 4-in. ANSI B16.9 Tees
,” Welding Research Council Bulletin, Paper No. 304.
5.
Junker
,
A. T.
, 1985, “
Finite Element Determination of the Limit Load of a Nozzle in a Cylindrical Vessel Due to In-Plane and Out-of-Plane Moments
,” Swanson Engineering Associates Corporation (SEAC) Report No. SEAC-TR-312, Rev. 2, to the Pressure Vessel Research Committee, WRC, New York.
6.
Moffat
,
D. G.
, 1985, “
Experimental Stress Analysis of Four Fabricated Equal Diameter Branch Pipe Intersections Subjected to Moment Loadings and Implications on Branch Junction Design
,”
Proc. Inst. Mech. Eng.
0020-3483,
199
(
4
), pp.
261
–
284
.
Crossref
Search ADS
 
7.
Moffat
,
D. G.
,
Mwenifumbo
,
J. A. M.
,
Xu
,
S. H.
, and
Mistry
,
T.
, 1991, “
Effective Stress Factors for Piping Branch Junctions Due to Internal Pressure and External Moment Loads
,”
J. Strain Anal.
0022-4758,
26
(
2
), pp.
85
–
101
.
Crossref
Search ADS
 
8.
Rodabaugh
,
E. C.
, 1988, “
A Review of Area Replacement Rules for Pipe Connections in Pressure Vessels and Piping
,” Welding Research Council Bulletin, Paper No. 335.
9.
Rodabaugh
,
E. C.
, 1976, “
Interpretive Report on Limit Analysis and Plastic Behavior of Piping Products
,” Welding Research Council Bulletin, Paper No. 254.
10.
Kalnins
,
A.
, 2001, “
Guidelines for Sizing of Vessels by Limit Analysis
,” Welding Research Council Bulletin, Paper No. 464.
11.
Chapuliot
,
S.
,
Moulin
,
D.
, and
Plancg
,
D.
, 2002, “
Mechanical Behavior of a Branch Pipe Subjected to Out-of-Plane Bending Load
,”
ASME J. Pressure Vessel Technol.
0094-9930,
124
, pp.
1
–
14
.
12.
Mourad Hashem
,
M.
, and
Maher
,
Y. A.
, 2002, “
Limit-Load Analysis of Pipe Bend Under Out-of-Plane Moment and Internal Pressure
,”
ASME J. Pressure Vessel Technol.
0094-9930,
124
, pp.
32
–
37
.
Crossref
Search ADS
 
13.
Widera
,
G. E. O.
, and
Wei
,
Z.
, 1998, “
Parametric Finite Element of Large Diameter Shell Intersection, Part 2, External Loading
,” PVRC Project No. 96-20AS, WRC, New York.
14.
Sang
,
Z. F.
,
Wang
,
Z. L.
,
Xue
,
L. P.
, and
Widera
,
G. E. O.
, 2005, “
Plastic Limit Loads of Nozzles in Cylindrical Vessels Under Out-of-Plane Moment Loading
,”
Int. J. Pressure Vessels Piping
0308-0161,
82
, pp.
638
–
648
.
Crossref
Search ADS
 
15.
Swanson Analysis System Inc.
, ANSYS Engineering Analysis Systems User’s Manual.
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